1. Field of the Invention
The present invention generally relates to removing material, for example, by machining diverse objects, or by marking and inscribing objects such as gemstones, particularly diamonds, with indicia identifying the gemstones. The material removal is performed by ultrasonically vibrating a solid backing fused to abrasive particles that fill cutouts in a mask, the cutouts being arranged in a pattern corresponding to the identifying indicia, or in a machining pattern.
2. Description of the Related Art
Laser etching or inscribing of a diamond surface for the purpose of permanently identifying a diamond is well known. U.S. Pat. No. 4,392,476; No. 4,467,172; No. 5,753,887; No. 5,932,119; No. 5,149,938; No. 5,410,125; No. 5,573,684; No. 6,211,484 and application Ser. No. 09/785,631 filed Feb. 16, 2001 now U.S. Pat. No. 6,483,073 are representative of the prior art of laser marking systems that employ lasers, beam delivery and imaging components, gemstone fixtures, servomotors, optical encoders, and programmed computers for controlling the marking procedure.
Such marking systems not only occupy a large volume of space to accommodate all of their various components, but also are costly to purchase and operate. As a result, such systems are typically installed at one or more authorized sites, such as a gemological laboratory or institute. Jewelers and like customers desiring gemstones to be marked send the gemstones to the site of the marking system, and wait for the marked gemstones to be returned.
Many jewelers dislike sending precious items out of their hands and, hence, out of their sight and control, but perhaps, more importantly, dislike having to wait for their return. Yet, the size and cost of laser marking systems dictate against the average small jeweler's purchasing and installing such a system at the jeweler's premises. Such systems also require skilled, trained personnel to operate the system. This requirement is typically difficult for the average jeweler to meet.
I previously proposed in U.S. patent application Ser. No. 09/858,846, now U.S. Pat. No. 6,662,716 filed May 16, 2001, a flame marking system and method in which a flammable substance filled cutouts in a tape, and was thereupon ignited to scorch a gemstone in a burn pattern corresponding to the cutouts and the indicia to be marked. This technique required close monitoring of the flame produced after ignition to avoid the risk of fire. I also earlier proposed in U.S. patent application Ser. No. 09/909,174, now U.S. Pat. No. 6,593,543 filed Jul. 19, 2001, a gemstone marking system and method in which a radiant energy source caused a fusible coating to be fused on and in the surface of a gemstone in a marking pattern. In one embodiment, the fusible coating filled cutouts in a stencil. The energy source was preferably a laser, but could have been a radio frequency or microwave source. In both of my earlier applications, the marking was achieved at a jeweler's premises.
It is also known to drill or bore holes through or in objects by using a high energy laser, or by ultrasonic drilling especially with brittle objects. The size of the ultrasonic drill bit dictates the size of the hole and, hence, such techniques are unsuitable for complex machining patterns or indicia patterns.
I also previously proposed in U.S. patent application Ser. No. 10/035,715, filed Oct. 22, 2001, now U.S. Pat. No. 6,612,906 a vibratory material removal system and method in which an ultrasonic vibrator agitated a liquid mixture containing abrasive particles that filled cutouts in a mask applied to an object from which material was to be removed. The use of liquid was messy, under certain circumstances, and evaporated after prolonged agitation. Also, the mixture tended to seep under the mask and resulted in some unwanted material being removed from the object.